Electric filament lamp with improved filament supporting means

ABSTRACT

In order to obtain a good fixation of the location of the filament in the envelope of an electric incandescent lamp, in particular a miniature lamp, a slit or pit-like depression is made in the bottom of the envelope against the sides of which the bent ends of pole or supporting wires present in the lamp are located.

United States Patent [191 Middelhoek et al. 1 May 29, 1973 [54] ELECTRIC FILAMENT LAMP WITH [56] References Cited IMPROVED FILAMENT SUPPORTING UNITED STATES PATENTS MEANS 75 Inventors: Joris Leenden Middelhoek; Joseph 1,983,362 12/1934 Geiger et al. ..3l3/27l X Willem Snudo, Temeuzen, Nether; 3,294,998 l2/l966 Niles ..313/317 x ands FOREIGN PATENTS OR APPLICATIONS [73] Assignee corlmafim New 571 947 3/1959 Canada ..3l3/269 York, N.Y.

[22] Filed: June 25, 1971 Primary ExaminerRonald L. Wibert Assistant ExaminerPaul A. Sacher [21] Appl' 156857 Attorney-Frank R. Trifari [30] Foreign Application Priority Data [57] ABSTRACT July 3,1970 Netherlands ..7009852 I order t bt in a ood fixation of the location of the filament in the envelope of an electric incan- U-Su Cl. a a l5, descent lamp particular a miniature lamp, a or 31 3/317 pit-like depression is made in the bottom of the en- [51] Int. Cl. .1101] 1/94 velope against the sides of which the bent ends of pole [58] Fleld of Search ..3l3/2g?5/237l17, 237185, Dr Supporting wires present in the lamp are located.

2 Claims, 6 Drawing Figures Patented May 29, 1973 2 Sheets-Sheet 1 Fig.1c

INVENTORS WMIDDELHOEK SNUDO 2 Sheets-Sheet 2 Fig.2b

I Fig.2c

AGENT ELECTRIC FILAMENT LAMP WITH IMPROVED FILAMENT SUPPORTING MEANS Known is an electric filament lamp comprising an envelope having a jacket and a bottom, the lamp comprising at least two wires sealed in the lamp set, which wires, viewed from the lamp set, extend beyond the filament and are each provided with a bent part extending at right angles to the axis of the lamp, the parts being separated from each other by a projection occurring on the bottom of the envelope and extending in the lamp space.

The object of this known construction which is used, for example, in miniature lamps having a lens-shaped bottom, is to protect the filament as much as possible from vibrations which could be detrimental both to the life of the filament and to the prescribed location of the filament in the lamp. In the known lamp the part of the lens extending in the lamp space serves as a projection. The bent wire ends bear in the sharp transition between said lens part and the jacket of the envelope. These ends of the wire must be bent so as to obtain the desired fit.

In this known lamp, there is a comparatively sharp angle formed in the region of the circular sharp transition between the bottom of the envelope and the jacket. For this reason, it is important in the manufacture of this type of lamp, that the lamp set is carefully sealed in the envelope so that the bent ends of the wire do indeed lie in the transition. Otherwise the desired positions of the filament in the envelope is not achieved.

In accordance with the present invention, while maintaining a substantially fixed location of the filament relative to the remaining parts of the lamp, larger tolerances are permissible in manufacturing the lamp and in its design. For that purpose, the lamp of the type according to the present invention is characterized in that the projection extending in the lamp space comprises wall parts which extend over some distance along the wires having the bent ends, the bent wire parts being enclosed in the space(s) in the direction of the lamp axis. If desirable, the wire is enclosed in the space with a small amount of play permitted. The space(s) are present between the envelope jacket and the projection on the bottom of the envelope.

According to a favorable embodiment of the lamp according to the invention, the projection extending in the space of the envelope consists of a depression provided in the bottom of the envelope from without. This bulge may be in the form of a pit or a slit.

In a further favorable embodiment of the lamp according to the invention, the bent ends of the wires which, viewed from the lamp set extend beyond the filaments, are straight. The operation of bending the wire ends in this manner is simpler than that which has to be carried out with the above-described ends of the wire present in the known lamp. The wires comprising the bent ends may be the stiff current-conducting lamp pole wires.

The invention is particularly suitablefor use in a lamp in which the rather long slack supporting wires comprise the bent ends. This is the case, for example, in signalling lamps incorporated in push-buttons. Each time a push-button is depressed, a considerable shock is exerted on the lamp set present in the lamp, so that said set and the supporting wires start vibrating and hence the elongate filament may be damaged. By arranging the ends of the wires in the manner proposed by the invention, the vibration of the supporting wires is substantially entirely damped when a shock is exerted on the lamp. The life of such a lamp is long.

In order that the invention may be readily carried into effect, two embodiments thereof will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which:

FIGS. la, lb and 1c are a front elevation, a side elevation and a plan view, respectively, of a first embodiment of the lamp according to the invention,

FIGS. 2a, 2b and 20 also are a front elevation, a side elevation and a plan view, respectively of a second embodiment of the lamp according to theinvention.

The lamp shown in FIG. 1 is of the so-called foot assembly type. Four wires are sealed in the bead l which consists of glass or another insulating material. The wires 2 and 3 are the lamp pole wires. They extend through the bead l and their lower ends 4 and 5 are sealed in the transition between the jacket 6 of the envelope and the tipped-off end of the exhaust tube 7. In the hook-like ends 8 and 9 of said pole wires, the ends of a stretched filament 10 consisting of straight wire material are clamped. This filament is kept stretched by the long, rather slack supporting wires 11 and 12 which are also incorporated in the bead 1. As is shown in particular in FIG. lb for the supporting wire 11, which is visible in this Figure, each of the supporting wires 11 and 12 comprises a V-shaped bent part. The filament 10 bears in the corner which is present between the limbs 13 and 14 of each of said V-shaped bent parts, so that said filament is kept in the prescribed stretched position.

In order to prevent said filament from prematurily reaching the end of its life, for example, due to vibrations of the lamp set, each of the supporting wires 11 and 12 is provided, beyond the filament, with bent ends 15 and 16, respectively, extending transverse to the lamp axis and incorporated in the space present between the wall parts of a projection 17 extending in the lamp space and the jacket-shaped part of the envelope 6, see also FIG. 1c.

As shown in FIGS. la and lb, the bent wire parts are entirely enclosed between the jacket 6 and the projection 17. In directions transverse to the lamp axis, the bent wire parts are substantially immovable. Also with a view to manufacturing tolerances it is desirable that the wire parts 15 and 16 should be present in the space destined for them with some amount of vertical play, i.e., in the direction of the lamp axis.

In this embodiment of the lamp according to the invention, the projection extending inside the lamp space is formed by a local slit-shaped depression in the material of the bottom of the envelope.

The embodiment of the lamp according to the invention shown in FIG. 2 in principle corresponds to that shown in FIG. 1, so that reference can be made to FIG. 1 as regards the general construction of the lamp. In the lamp shown in FIG. 2, however, the projection extending in the lamp space is formed by a pit-like depression 18in the bottom of the envelope. The bent wire ends 19 and 20 extend in a transverse direction and are fixed in the channel-like space between wall parts of said depression and the inside of the envelope; in this case also the bent wire ends 19 and 20 maintain some amount of play in a vertical direction in the channel-shaped space.

What is claimed is:

1. An electric incandescent lamp comprising:

an envelope, said envelope having jacket and a bottom, the bottom of said envelope including a projection extending into the internal space of the lamp, the projection defining recesses within the lamp having walls formed by the projection and the jacket;

a lamp set, including an insulative bead, means to .support the bead, and a filament, said filament extending along the longitudinal axis of the lamp; and

at least two wires sealed in the lamp set, said wires extending along said axis of the lamp beyond the filament, each of the wires being provided with a bent part, said bent part extending transverse to said longitudinal axis, the bent parts being positioned within said recesses with the bent parts juxtaposed 5 to and pressing the walls of the projection, said bent parts also having a limited amount of longitudinal axis play. 2. An incandescent lamp as in claim 5 wherein said wires are supporting wires for the filament and include a V-shaped filament supporting portion and wherein the bent end portions of the wire placed within the recesses are straight.

it i t t l 

1. An electric incandescent lamp comprising: an envelope, said envelope having jacket and a bottom, the bottom of said envelope including a prOjection extending into the internal space of the lamp, the projection defining recesses within the lamp having walls formed by the projection and the jacket; a lamp set, including an insulative bead, means to support the bead, and a filament, said filament extending along the longitudinal axis of the lamp; and at least two wires sealed in the lamp set, said wires extending along said axis of the lamp beyond the filament, each of the wires being provided with a bent part, said bent part extending transverse to said longitudinal axis, the bent parts being positioned within said recesses with the bent parts juxtaposed to and pressing the walls of the projection, said bent parts also having a limited amount of longitudinal axis play.
 2. An incandescent lamp as in claim 5 wherein said wires are supporting wires for the filament and include a V-shaped filament supporting portion and wherein the bent end portions of the wire placed within the recesses are straight. 